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// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-%typedarray%.prototype.fill
description: Consistent canonicalization of NaN values
info: |
22.2.3.8 %TypedArray%.prototype.fill (value [ , start [ , end ] ] )
%TypedArray%.prototype.fill is a distinct function that implements the same
algorithm as Array.prototype.fill as defined in 22.1.3.6 except that the this
object's [[ArrayLength]] internal slot is accessed in place of performing a
[[Get]] of "length". The implementation of the algorithm may be optimized with
the knowledge that the this value is an object that has a fixed length and
whose integer indexed properties are not sparse. However, such optimization
must not introduce any observable changes in the specified behaviour of the
algorithm.
...
22.1.3.6 Array.prototype.fill (value [ , start [ , end ] ] )
...
7. Repeat, while k < final
a. Let Pk be ! ToString(k).
b. Perform ? Set(O, Pk, value, true).
...
24.1.1.6 SetValueInBuffer ( arrayBuffer, byteIndex, type, value [ ,
isLittleEndian ] )
...
8. If type is "Float32", then
a. Set rawBytes to a List containing the 4 bytes that are the result
of converting value to IEEE 754-2008 binary32 format using “Round to
nearest, ties to even” rounding mode. If isLittleEndian is false, the
bytes are arranged in big endian order. Otherwise, the bytes are
arranged in little endian order. If value is NaN, rawValue may be set
to any implementation chosen IEEE 754-2008 binary64 format Not-a-Number
encoding. An implementation must always choose the same encoding for
each implementation distinguishable NaN value.
9. Else, if type is "Float64", then
a. Set rawBytes to a List containing the 8 bytes that are the IEEE
754-2008 binary64 format encoding of value. If isLittleEndian is false,
the bytes are arranged in big endian order. Otherwise, the bytes are
arranged in little endian order. If value is NaN, rawValue may be set
to any implementation chosen IEEE 754-2008 binary32 format Not-a-Number
encoding. An implementation must always choose the same encoding for
each implementation distinguishable NaN value.
...
includes: [nans.js, testTypedArray.js, compareArray.js]
---*/
function body(FloatArray) {
var sample = new FloatArray(3);
var control, idx, someNaN, sampleBytes, controlBytes;
for (idx = 0; idx < distinctNaNs.length; ++idx) {
someNaN = distinctNaNs[idx];
control = new FloatArray([someNaN, someNaN, someNaN]);
sample.fill(someNaN);
sampleBytes = new Uint8Array(sample.buffer);
controlBytes = new Uint8Array(control.buffer);
assert(compareArray(sampleBytes, controlBytes), 'NaN value #' + idx);
}
}
testWithTypedArrayConstructors(body, [Float32Array, Float64Array]);
|